This study investigates the self-healing capabilities of Ultra-High Performance Concrete (UHPC) under the combined influence of mechanical and environmental factors. Specifically, it delves into the long-term self-healing process in pre-cracked UHPC samples that endure continuous sustained tensile stresses across the cracks and are exposed to aggressive environmental conditions for one year. The results reveal that UHPC with narrow cracks exhibits a higher degree of self-healing, especially when exposed to tap water, where its self-healing capacity is most pronounced and improves with extended exposure. Furthermore, these self-healing mechanisms contribute to the restoration of mechanical properties and prevent chloride ion penetration by sealing the cracks. While a reduced level of self-healing is observed in saltwater and geothermal water exposure, prolonged exposure mitigates the inhibitory effect of aggressive ions on self-healing. SEM and EDS results provide evidence that samples subjected to extended exposure to salt and geothermal water exhibit a substantial presence of self-healing product-CaCO₃. This study not only emphasizes that pre-cracked UHPC, when exposed to both mechanical stresses and aggressive environments, can maintain excellent durability and mechanical strength due to its self-healing effect but also lays the foundation for evaluating the self-healing potential of cement-based materials under conditions representative of real-world structural scenarios. This is essential for advancing the integration of self-healing advantages into design concepts and performance-based verification approaches.

本研究研究了超高性能混凝土（UHPC）在机械和环境因素综合影响下的自修复能力。具体来说，它深入研究了预裂纹 UHPC 样品的长期自修复过程，这些样品在裂纹上承受持续的拉伸应力，并暴露在恶劣的环境条件下一年。结果表明，具有窄裂纹的 UHPC 表现出更高程度的自修复能力，尤其是在暴露于自来水时，其自修复能力最为明显，并且随着暴露时间的延长而增强。此外，这些自愈机制有助于恢复机械性能，并通过密封裂缝来防止氯离子渗透。虽然在暴露于盐水和地热水中观察到自愈水平降低，但长时间暴露会减轻侵蚀性离子对自愈的抑制作用。SEM 和 EDS 结果证明，长期暴露于盐和地热水的样品表现出大量存在的自修复产物 - CaCO ₃。这项研究不仅强调了预裂UHPC在暴露于机械应力和侵蚀性环境时，由于其自​​修复效应而能够保持优异的耐久性和机械强度，而且为评估水泥基材料的自修复潜力奠定了基础。基于代表现实世界结构场景的条件下的材料。这对于推动将自愈优势集成到设计概念和基于性能的验证方法中至关重要。